Operating mechanism for injector overflow valves



June 4, 1940. f

E. RAwsoN OPERATING MECHANISM FOR INJECTOR OVERFLOW VALVES Filed April v2, 1938 l N V E N TO R L 'mama/l Eau/svn ATTORNEY Gir - which is the cab II.

Patented June 4, 1940 g UNlTED STATES OPERATING MECHANISM FOR INJECTOR OVERFLOW VALVES Emanuel Rawson, Chicago, Ill., assigner to The Superheat'er Company, New york, N. Y.

Application April 2, 193s, serial No. 199,576

5 Claims.

This invention relates to injectors and has particular reference to exhaust steam injectors for steam locomotives. invention relates to means for holding the overl iiow valve of such an injector closed when it is desired to blow steaminto the water suction line to clear it or the suction strainer of obstructions and also to prevent the escape of steam admitted to the injector to prevent freezing while out of operation during cold weather. l

One type of mechanism heretofore employed to hold the overflow valve closed for the `purposes mentioned consists of a spindle threadedly mounted in a bracket on the injector casing in alinemcnt with the overflow valve stem so that the spindle may be screwed down to operatively engage the'valve stem for positively holding the valve closed. Due to the fact that the injector is mounted beneath the locomotive cab and the controls therefor are mounted in the cab, it has been customary to interpose a series of rotatable rods interconnected by universal joints between the aforesaid spindle on the injector' casing and the control wheel or handle in the locomotive cab. Although this mechanism is operated only occasionally to provide for blowing back of the suction line or heating of the injector, it is nevertheless subjected to considerable wear due to vibration because the jointed construction of such a valve operating mechanism results in vibration producing wear of the parts.

An object of the present invention is to provide an improved mechanism for operating the overiiow valve in` which wear due to vibration is substantially eliminated.

Another object of the invention is to provide means for protecting delicate mechanism such as indicating gauges or control operating bellows associated with the injector against excessive 'y steam pressures within thel injector when live I of a locomotive equipped with an injector embodying the present invention; l

Fig. 2 is an enlarged sectional View on the line 2-2 in Fig. 1; and

Fig..3 is an enlarged sectional view on the line 3 3 in Fig. 2 showing certain details of theA injector construction.

Referring to Figfl, the numeral iii designates the boiler of a locomotive at the rear end oi Located beneath the cab is an exhaust steam injector, indicated generally at A, which for purposes of illustration is shown as being as the kind shown and described in United States Patent 1,870,006, granted August 2, 1930, to Malcolm Hard, to which reference may be had Still more particularly the for details of construction not described herein. It will be understood that the present invention is also applicable to other types and kinds of injectors, including live steam injectors.

' Exhaust steam is supplied to the injector A from the exhaust passages of the locomotive cylinders through pipe l2. Live steam is'supplied from the boiler turret i3 through the live steam supply pipe I 4 for operating the injector in conjunction with exhaust steam, for operating the injector as live steam injector when exhaust steam is not available, for clearing the suction line of obstructions or for heating the injector to prevent its freezing. Flow of steam through pipe I4 is regulated by the remote control valve l5 located in a convenient position in the cab of the locomotive. Water is supplied'to the injector from the locomotive tender (not shown) through the suction pipe I3 and the amount of water supplied to the injector is controlled by means of f the operating handle Il also located in the locomotive cab. A dual gauge 2li inthe locomotive cab is connected by gauge pipes 2l and ZZ to the low pressure chamber 23 (Fig. 2) and the overiiow chamber 24, respectively, of the injector so that observation of the two needles of-the gauge may serve to inform the leman of theccnditions under which the injector isfoperating. The injector is also provided with an exhaust pressure regulator for automatically amount of exhaust steam supp-lied to the injector in order that the maximum amounts of exhaust steam may be utilized under various conditions of operation. As described in copending application Serial No. 185,548, led January 18, 1938, this regulator consists of a bellows device 25 subjected through a pipe 2t to the pressure existing in the overflow chamber 24 of the injector- An increase of pressure in the overflow chamber results in compressing the bellows 25 which then acts to close a butterfly valve El in a passage 28 leading to the space between the draft nozzle 30 and the vacuum nozzle 3l of the injector.

The passage from the overilow chamber 24 to the overflow pipe 32 of the injector iscontrolled by an overflow valve 33 (Fig. 3) which rests upon Ia seat at the upper end of the chamber.` When the injector isfunctioning normallyv and delivering water, the delivery pressure is communicated to a piston 34r which acts through a lever 35 en- F.

controlling the injector, the following mechanism is provided. Supported on a bracket 40 on the injector casing is a cylinder 4| open at its lower end and containing a plunger 42 which is alined with the stem 35 of valve 33. A spring 43 mounted between a shoulder 44 on plunger 42 and another near the base of the cylinder bore is provided for moving the plunger into engagement with lever 35 which overlies the end of the stem 36 of the overflow valve. The inner end of plunger 42 is connected to one end of a cable 45 closely tting within a exible sheath or tube 46 and extending to a convenient location Within the locomotive cab. At the cab end the cable is connected to a threaded slide or spindleI 41 mounted in a bracket 48 and held against rotation by a stud 5|] carried by the bracket and engaging a longitudinal groove 5| in the spindle. A hand wheel 52 threaded on the spindle 41 is held against bracket 48 by spring 43 racting through cable 45. When the hand wheel 52 is turned clockwise it causes movement of the spindle 41 to the left, Fig. 3, and retracts the plunger 42 from engagement with the lever 35 which lies between the end of the plunger and the valve stem 36. This action results in compressing the spring 43 so that it holds the plunger 42, the cable and the spindle 41 under tension and thus minimizes wear of Vthese parts due to vibration by holding them against any substantial movement.

When it is desired to admit live steam to the injector either for the purpose of clearing the suction line or to prevent freezing of the injector, the overflow valve 33 must be held in closed position. To accomplish this the hand Wheel 52 is turned counter-clockwise and this results in spring 43 acting to move the plunger 42 into operative engagement with the lever 35 which contacts the stem 36 of the overflow valve. As the hand wheel is operated to permit plunger 42 to be projected from. the cylinder 4I to hold the overflow valve closed, the load of the spring 43 is transferred from plunger 42 to the overflow valve 33. The initial compression of spring 43, when the plunger is releasably held in retracted position, is such that when the load of the spring has been transferred to valve 33 sufficient energy remains stored in the spring so that it functions as a load for the overflow valve. Consequently, the overflow valve is converted to a relief valve which serves to protect the indicating gauge 20 and the bellows 25 against excessive pressure when valve l5 is opened to supply live steam to the injector. If during the time that steam is being admitted to the injector While overflow valve 33 is closed for the purpose of blowing back the suction line or heating the injector, a pressure should be built up in the injector which might result in injury to the gauge 20 or bellows 25, the overflow valve 33 opensautomatically at the time the pressure exceeds the load aorded by the spring 43.

Although an illustrative embodiment of the invention has been shown and described in detail herein it is to be understood that various changes and variations may be made without departing from the invention, and therefore it is intended to include all such changes and variations Within the scope of the appended claims.

What I claim is:

1. In an injector having a normally closed overflow valve controlling communication between its overflow chamber and its overflow pipe;

' with said valve and acting to energize said spring so that it holds said plunger and cable uncle tension to eliminate vibration thereof.

2. In an injector having a normally closed overflow valve controlling communication between its overflow chamber and its overow pipe;

a plunger movable to operatively engage said,A

valve for holding it closed; a cable attachedat one end to said plunger; releasable means associated with the other end of said cable for holding said plunger in a retracted position out of said operative engagement with said valve; and a compression spring mounted between said plunger and a xed support and acting to maintain said plunger and cable under tension for eliminating vibration, said spring acting upon release of said holding means to move said plunger into opera tive engagement with said valve and to hold the latter closed.

3. In an injector having a normally closed overflow valve controlling communication between its overflow chamber and its overflow pipe; a plunger movable to operatively engage said valve for holding it closed; a cable attached 'at one end. to said plunger; releasable means associated with the other end o-f said cable for hold-- ing said plunger out of operative engagement with said valve; and a spring .acting on said plunger, upon, release of said holding means, to move it into operative engagement with said valve, the force stored in said spring being such that after it moves said plunger to operative engagement with said valve it retains suiicient energy to constitute a load for said valve.

4. In an injector having a normally closed overflow valve controlling communication between its overflow'chamber and its overflow pipe; a movable plunger positioned out of operative engagement with said valve; a spring urging said plunger into operative engagement with said valve to hold it closed; a cable attached at one end to said plunger; and means associated with the other end of said cable operable to move and hold said plunger in its retracted position out of operative engagement with said valve and acting to energize said spring so that it holdsv said plunger and cable under tension to eliminate vibration thereof.

5. In an injector having a normally closed overflow valve controlling communicationfbe` tween its overflow chamber and its overflow pipe, means for admitting steam to the interior of said injector including said chamber thereof, and

means in communication with the interior of said injector and responsive to pressure conditions therein; a member operable to hold said valve in closed position when the injector is out of opera-A tion and it is desired toretain steam under pressure Within the injector; and a spring associated with said member and valve and acting, when said member is eifective to close said valve, as a yieldable load for said valve to protect'said pressure responsive means against excessiv steam pressures within said injector.l f

EMANUEL RAWSON.V 

